Please refer to FIG. 1, which is a schematic diagram showing a typical TV card 1. There are principally two sets of I/O terminals, wherein the first one is a TV signal transmission connector 110 of a channel tuner 11, i.e. so-called RF connector, and the second one is an AV terminal socket set 12 that typically consists of three AV terminals for left/right audio and video connections, i.e. so-called RCA connector.
For complying with the requirements of three major environmental stipulations in European, i.e. WEEE, RoHS and EUP, an adapter manufacturers need to electrically connecting the TV signal transmission connector 110 and the AV terminal socket set 12 disposed on a circuit board to a securing plate 13 coupled to a computer casing (not shown). In this conductively grounding way, electrostatic discharge (ESD) protection can be achieved and noise interference can be reduced from the signal transmitted through the TV signal transmission connector 110 and the AV terminal socket set 12. So far, there have been only copper rings, aluminum foils, conductive foams and spot welding material used as the conducting, grounding and noise-eliminating means. Among the means, copper ring washers 14 are the most popular, which are inserted between the TV signal I/O connector 110/AV terminal socket set 12 and the securing plate 13. As the clearance between the TV signal transmission connector 110/AV terminal socket set 12 and the securing plate 13 may vary with products, copper ring washers with various thicknesses need be prepared by the manufacturer to fit possibly various clearances between the securing plate 13 and the connectors 110 and 12. The stock material would increase manufacturer's cost. Moreover, conventionally used copper ring washers containing high cadmium (Cd) contents may fail the RoHS stipulations and become environmentally unacceptable in European Union.
The electric connection between the TV signal transmission connector 110 and the AV terminal socket set 12, if accomplished by aluminum foil seal or conductive foam seal (not shown), would uglify the product and thus lower the value of the product. In addition, because the aluminum foil or conductive foam is applied by adhesion, the limitation in space would deteriorate the adhesion and thus result in stripping or damage of the aluminum foil or conductive foam. Moreover, the grounding feature is highly affected by the quality of the adhesive, so the anti-noise performance is hard to be controlled.
On the other hand, though the electric connection conducted by spot welding (not shown) is a better solution than aluminum foil seal in good contact between the TV signal transmission connector 110 and the AV terminal socket set 12, it still result in low-valued appearance of the product. In addition, the manufacturing cost will be adversely affected due to the extended laboring.